Differential equations [for sine sums]

The function Sin[x] + Sin[Sqrt[2] x] can be obtained as the solution of the differential equation y''[x] + 2 y[x] - Sin[x] == 0 with the initial conditions y[0] == 0, y'[0] == 2.

Differential equations [for sine sums]

The function Sin[x] + Sin[Sqrt[2] x] can be obtained as the solution of the differential equation y''[x] + 2 y[x] - Sin[x] == 0 with the initial conditions y[0] == 0, y'[0] == 2.

From Stephen Wolfram: *A New Kind of Science* [citation]